I don’t think this is a case of trying to make more money.

Sure it is: the only reason for DRM is to make more money.

What we’re seeing with Reddit is just the first stage of enshittification: making things worse for the end users who have been captured by network effect and what used to be a good service, in order to benefit advertisers. The second stage is making things shitty for the advertisers who have been captured by all the captive users. Paid subs are probably a harbinger of that kind of thing, but I don’t think advertisers are locked in enough to be really stuck yet.